Tens of thousands of music and football fans filled the Crossroads of the World yesterday for the world’s biggest tailgate party – a 3 1/2-hour extravaganza featuring Bon Jovi, Alicia Keys, Eve and Enrique Iglesias.

“We did it because we love Bon Jovi and we love football,” Longo said. After the mega-event, he and Guarnieri went back to her house to watch the New York Giants battle the San Francisco 49ers in the first game of the NFL season.

The exuberant crowd – under the steely gaze of 5,700 cops – went wild when Jon Bon Jovi took the huge T-shaped stage to close the show with half a dozen songs, including “Everyday,” from his new album, “Bounce.”

The party was held to kick off the new NFL season and to show that the Big Apple is back on track after Sept. 11.

“It’s stuff like this that makes the city come alive following the attack,” said Michelle Lapuente, 27, of Brooklyn. “We’ve had too much sadness over the last 12 months. It’s time to enjoy ourselves.”

Brian Scott, 38, of Manhattan, agreed, saying, “I just came out here today because it’s good to be together alongside my fellow New Yorkers.”

In the concrete canyon between Broadway and Seventh Avenue, a wall of people stretched from 43rd Street, where the stage was set up, to 49th Street. Those unable to find a place in front of the stage watched the show on one of five jumbo TV screens.

“This is great – a little music and a little football. I’m in heaven,” said John Martini, 34, of Floral Park, L.I.

Joanne McDonald, 40, of Manhattan, who was wearing a Giants T-shirt, was also in a New York state of mind. “If anyone ever had any doubt that New Yorkers could hold a party, this should silence all the critics,” she said. “This is absolutely amazing.”

A fellow Giants fan, Josh Daniels, 22, of Brooklyn, said, “Today, this is the center of the universe.”

Linda Roman, 43, of Puerto Rico, said she hadn’t visited the Big Apple in 20 years. “Today has what I’ve missed – the energy, the people,” she said.